Cut yourself plenty of slack.  Get away with doing as little as possible, and do as much of that little, ahead of time.  You're just not going to feel in the swing so accept that this years Christmas will be different.	Keep an eye on your drinking and eating and make sure you get as much rest as possible, even if it means crawling back into bed after the kids have opened their presents.
This year I'm compensating for my lack of organisation by putting the decorations up a little earlier.	When you're sickened to the back teeth by media images of  ecstatic families remember that such families are the minority.  Only a tiny percentage of society is made of such.
Keep coming to the community, it's business as usual over the holdiay period and we will still be about to post or a chat.	Don't allow yourself to feel guilty about rushing around less, in many ways it's good to learn that Christmas comes and goes, and is just as good for the kids regardless of whether you've been rushing about like a headless chicken for weeks/months.
Avoid the urge to compensate for your 'aloofness' by spending more on presents and all the trimmings.	Do something different, if you haven't before consider a Christmas morning Church service, or if you're single, look into helping out at a homeless shelter for the day.
Think about what you want Christmas to mean to you.  If you're not religous give it your own meaning, whether it's the love you have for your children or a time to forgive and make peace.	If you want, cut right back on entertaining,  If you're not up to a big family gathering then consider skipping it for this year, if it makes you feel better plan to see them when you are more 'up to it'.